This invention relates to a clip apparatus and, in particular, to a clip apparatus utilized in cholangiography and similar procedures wherein a catheter or the like is placed in a duct or vessel and held therein by a clamp mechanism.
Many medical procedures require that a catheter, tube or the like be placed in a body duct or vessel and held therein while some medical procedure is performed. For example, plastic catheters are often placed in veins and held therein by a stitch or by a loop of string tied around the catheter. Similarly, a tubular structure must be held within a vessel during a lymphangiogram or in an IV cut down procedure. During cholangiography, a cannula must be sealably held within the cystic duct.
In humans, the common bile duct joins the liver with the duodenum to provide flow of bile from the liver to the small intestine to assist in the digestion of fats. The gallbladder is a sac-like structure which communicates with the common bile duct through the cystic duct and provides intermittent storage for excess bile produced by the liver, especially between meals. Gallstones sometimes occur in the bile and block or impede flow of the bile through the various ducts. When this occurs, the gallbladder may have to be surgically removed (cholecystectomy).
To ensure removal of all gallstones from the common bile duct, cholangiography is normally perfomed on the ductile system of the biliary tract which comprises the injection of a radiopaque dye into the duct followed by a series of x-rays. The x-rays tend to image the outlines of any stones or obstructions within the ducts, as variances in opacity occur where the stones prevent the dye from filling the duct.
Normally, the dye is injected into the common bile duct through a relatively small catheter which is inserted into a severed end of the cystic duct. It is important to form a relatively tight fluid seal between the cystic duct and the catheter. Such a seal prevents the dye from leaking out of the cystic duct rather than passing through the common bile duct to image the gallstones therein.
In order to produce such a tight seal, surgeons initially utilized a suture which was tied securely around the cystic duct to hold the catheter in place. Because it is difficult and cumbersome to tie the suture at this location, many surgeons have elected to utilize a commercially available metallic hemoclip for this purpose. The hemoclips were designed to have opposing walls which flatten against one another to flatten a severed blood vessel or the like to prevent leakage therefrom. As this type of clip was designed to compress flatly and not in a circle, there is a tendency for the tissue of the cystic duct to ovate when the clip is applied so that leakage occurs between the cystic duct and the catheter on the sides of the duct not compressed by the clip. In addition, the clip must be pried loose to remove.
Some complex mechanical clips have also been designed to be used for this purpose. However, such clips tend to be cumbersome as well as relatively expensive.
Hence, it was desired to produce a relatively simple clip which could be easily and quickly applied to the cystic duct which would compress the cystic duct fairly evenly about its entire circumference and which would be fairly easily removed after completion of the cholangiograpic process.
In addition, it was desired to have a catheter which would cooperate with the clip to provide a leak-proof seal. Further, it was desired to provide a tool which would both readily apply and remove the clip, as well as a process for utilization of the clip during surgical procedures.